The practice of using Geographic Information System (GIS) computer applications for storing and analyzing geospatial information and associated measurement data has been in place for decades. The purpose of a GIS is to collect and store geographically referenced data to allow subsequent modeling and distribution. The data is transferred to the GIS from remote devices capable of reporting GPS coordinates along with other sensor measurements. Traditional methods for transmitting geospatial data to a GIS require user interaction for both data input to the device and subsequently commanding the device to initiate transmission. Additionally, this communication is initiated by the remote device, which essentially pushes data to the GIS. The rate at which data is uploaded to the GIS is determined entirely by the operators of the remote devices, potentially impacting the accuracy of the GIS models.
To adapt these methods for use with remote, unattended sensor devices programmed to report data to the GIS, the GIS must be able to pull sensor and geospatial data from the devices or, at minimum, be able to query the devices for status updates. It is important for the server system to know the state of the remote devices due to the differing rate of geospatial data uploads between the devices and the unattended nature of the sensors. For example, an automated, unattended sensor device may include the capability to transmit geospatial data over a wireless network and, in order to preserve battery life, may be programmed to transmit that information infrequently to a GIS. In an emergency situation, users of that GIS may require sensor information on demand to provide an up-to-date operational picture. In situations such as those, it is advantageous for a GIS to include the capability to pull data from remote devices on demand instead of having data pushed to the system when available.